The Signaling System Number Seven (SS7) is a suite of protocols that were standardized in the 1980s in ITU-T Q.700 series. New protocols added in the 1990s and 2000s by ETSI and 3GPP to support mobile phones and the services they need (roaming, SMS, data…)
The Mobile Application Part (MAP) is an SS7 protocol that provides an application layer for the various nodes in GSM and UMTS mobile core networks and GPRS core networks to communicate with each other in order to provide services to mobile phone users. The Mobile Application Part is the application-layer protocol used to access the Home Location Register, Visitor Location Register, Mobile Switching Center,Equipment Identity Register, Authentication Centre, Short message service center and Serving GPRS Support Node (SGSN).
The MAP protocol is responsible for providing the following functionality:
Mobility Management, Operation and Maintenance, Call Handling, Supplementary Services and Short Message Service (Dryburgh, Hewet, 2005)
The Customized Applications for Mobile network Enhanced Logic (CAMEL) was introduced to allow mobile operators to build custom services that were not possible through MAP. The CAMEL Application Part (CAP) along with the Mobile Application Part (MAP) is going to be the focus of this paper.
SS7 was traditionally served over Time Division Multiplexing (TDM) networks; however with the increasing use of IP networks, SIGTRAN (Derived from Signal Transfer) was introduced as part of the SS7 protocol family but uses an IP protocol called Stream Control Transmission Protocol (SCTP) as the transport layer for SS7 (IETF, 1999).